Its only 20% electrical output, about the industry standart.

The rest is Thermal output, they combined solar electricity and solar heat in one pannel.

Prediction change all the time, and there are a lot of different ones out there, my point is not the exact number, but that the population growth does have a much bigger impact that fertilizer and wars.

Are you sure? Not the 1 billion more people per decade until 2050? (Prices and war, do have an impact, but not a high one)